Renogy 12V 30A/50A DC-DC On-Board Battery Charger with MPPT – Dual-Input Alternator & Solar Charger

Renogy 12V 30A/50A DC-DC On-Board Battery Charger with MPPT

The Renogy 12V 30A/50A DC-DC On-Board Battery Charger with MPPT is a smart, dual-input battery charger that keeps your auxiliary (house) battery topped up from two sources — your vehicle’s alternator and your solar panels. With an integrated MPPT solar controller, upgraded solar input up to 30V (30A model) or 50V (50A model), and intelligent charging logic that automatically switches between solar-only and hybrid charging, it’s the ideal charging heart for any RV, caravan, marine, or off-grid dual-battery system.

Dual-Input Charging – Alternator + Solar

The charger accepts input from both a starter battery (via the alternator) and solar panels, charging your auxiliary battery from whichever source is available. It works with both traditional alternators (13.2V–16V) and smart Euro 6 alternators (12V–16V), and when both solar and alternator are connected it intelligently selects between solar-only and hybrid charging based on available solar current.

Built-In MPPT Solar Charging

Maximum Power Point Tracking (MPPT) technology extracts the maximum available power from your solar panels throughout the day, automatically tracking the optimal voltage as weather and light conditions change — delivering up to 97% charging efficiency.

Intelligent Charging Logic & Low Solar Cutoff Mode

Advanced charging logic optimises performance in all weather conditions. A Low Current Cut-off Mode switches the charger to alternator-only charging when solar output drops below a set threshold (7–10A, configurable via the Renogy app), preventing inefficient trickle charging on cloudy days.

Four-Stage Charging Algorithm

• Bulk – constant current using 100% of available solar power
• Boost – constant voltage with gradually reducing current
• Float – constant low voltage to maintain a full charge (non-lithium)
• Equalization – for compatible flooded/vented lead-acid batteries only

Lithium battery activation is also supported — the charger provides a small current to reactivate sleeping LiFePO4 batteries whose BMS protection has been triggered.

All-in-One NEG-Terminal Design

The consolidated NEG-terminal design brings the solar array, starter battery, and house battery connections together in one place, optimising installation space and simplifying setup.

Comprehensive System Protections

• Undervoltage & overvoltage protection
• Overload & overtemperature protection
• Reverse current protection (protects solar panels from reverse charging at night)
• Reverse polarity & short circuit protection
• Soft-start circuit for enhanced battery stability

Smart Charging & Monitoring via App

With the optional Renogy BT-2 Bluetooth Module and the Renogy app, you can monitor your system in real time and adjust charging parameters remotely from your phone.

Battery Temperature Compensation

The included Battery Temperature Sensor measures temperature around the battery and compensates charging voltage for accurate, battery-safe charging in extreme conditions. (Note: do not use the temperature sensor on a LiFePO4 battery with its own built-in BMS.)

Ideal Applications

• RVs, caravans, and motorhomes
• Camper van and 4×4 dual-battery builds
• Boats and marine installations
• Overlanding and off-grid setups
• Auxiliary/house battery charging systems
• Solar-plus-alternator hybrid charging

Technical Overview

Important Setup Note

Always set the correct battery type before use — an incorrect battery type setting can damage the charger and voids the warranty. When using User Mode or customising a preset, consult your battery manufacturer’s recommended charging parameters first.

Choose the Renogy 12V 30A/50A DC-DC On-Board Battery Charger with MPPT for smart dual-input charging that keeps your auxiliary battery powered from both alternator and solar — the reliable heart of any RV, marine, or off-grid dual-battery system.